_Answer._ Either he or the fireman should _constantly_ watch the track in front of them, and also observe, from time to time, whether the train of cars, especially if it is a long one which he is handling, is in good condition. HE MUST OBSERVE EVERY SIGNAL SCRUPULOUSLY, AND SHOULD NEVER PASS ONE UNTIL HE IS SURE THAT HE IS AUTHORIZED TO DO SO. The well-known maxim, “be sure you are right; then go ahead,” should be changed for locomotive runners to, DON’T GO AHEAD UNTIL YOU ARE SURE YOU ARE RIGHT, AND WHEN IN DOUBT ALWAYS CHOOSE THE SIDE OF SAFETY. In running through curves, the speed of the train should always be moderated in proportion to the sharpness of the curve, and before reaching it. In running through curves, the tendency of the train is to continue in a straight line, and there is thus danger of running off the track. The higher the speed, of course, the greater is the resistance which is required to prevent the train from running in a straight line, and consequently the greater is the strain which is thrown on the flanges of the wheels and on the rails and axles. In running through curves, it is also impossible, usually, to see further than a short distance ahead, and therefore, if the train is running very fast, it cannot be stopped in time, should there be any obstruction or danger on the track. QUESTION 483. _What precautions should be observed in running over steep grades?_ _Answer._ On approaching an ascending grade the runner should see that the fire is in good condition, and as much coal should be put on it as can be burned to advantage. He should also fill the boiler as full of water as he safely can, without danger of priming, and should heat this water as hot as possible without blowing off steam at the safety-valves. The object of this is to have a supply of water already heated before reaching the grade. If, as often happens with a heavy train, the boiler will not make as much steam as the engine consumes, if there is a large supply of hot water in the boiler it can be used as a reserve, should it be necessary to do so, without danger of injury to the boiler. If there was so little water in the boiler that it would be dangerous to allow it to get lower, then it would be necessary to feed cold water as rapidly as the hot water escaped in the form of steam. It is often impossible to heat all this cold water as fast as it is pumped into the boiler, without reducing the steam pressure until there is then not sufficient power to pull the train. If, however, there is a supply of hot water in the boiler, at the critical point on the grade, where the engine is most liable to fail, the pump can be partly shut off, and thus less water will be pumped into the boiler, and the steam pressure be maintained without danger. Undoubtedly it is better to feed locomotive boilers uniformly, if that is possible, but it often happens that a reserve supply of hot water in the boiler enables an